Cao Hui says she really likes hanging out on the capital's prosperous shopping streets, but she often can't find a convenient public toilet.

"It's too difficult to find a washroom in shopping malls and you can't believe how long the waiting line is," said the 25-year-old civil servant. "And it is like finding a treasure box in a maze."

Hopefully, her problem will be solved within four years with the introduction of a text messaging service that will tell people where to find bathrooms nearby.

The messages will give the locations and routes for the public bathrooms nearest to scenic spots or downtown areas, Xie Guomin, head of the environmental sanitation division of the Beijing Municipal Commission of City Administration and Environment, told China Daily on Sunday.

"The specific measures of how to fix tourists' positions and the sender and the delivery means for the message are still under consideration," he said.

However, some experts said they didn't think the idea was workable.

"It sounds good, but it will be hard to carry out," said Jiang Zhongguang, a city planning professor at the Beijing University of Civil Engineering and Architecture.

What's most urgent, he said, was for the authorities to plan properly and relocate existing public toilets instead of relying too much on an attractive idea.

He also suggested that some public venues, such as banks and insurance companies, should open their washrooms to the public and help avoid overlapping investment on public facilities.

Sun Yue, 24, an employee at a local tourist agency, agreed with Jiang's remarks and said the text message idea wasn't practical.

"I'll have no time to check my phone if I'm like an ant on a hot pan finding a washroom," she said, adding that such messages could become a kind of spam since "they could swarm into my mobile phone" even when she didn't need to find a washroom.

Yi Shenghua, a lawyer at Beijing-based Yingke Law Firm, voiced his concern that this "well-intended" service might infringe on the public's privacy and lead to possible misuse of private information.

Under the current law, only public security authorities may monitor people's exact locations by using global positioning systems (GPS), Yi noted.

"So the commission has no right to fix where residents or tourists are", he added.

In October, a group of smartphone application developers in Nanjing, Jiangsu province, developed a GPS program that could locate the nearest public washroom in more than 20 cities around the country. The program has been downloaded by many smartphone users.